نتایج جستجو برای: microfossil

تعداد نتایج: 309  

Journal: :Perspectives of earth and space scientists 2022

James Ransom Heirtzler passed away in Silver Spring, Maryland, on 15 July 2022, at age 96. He was born Baton Rouge, Louisiana, 16 September 1925. served the U.S. Navy tropical and western Pacific during 1944–1946. graduated from New York University obtaining a Ph.D. Physics 1953 taught American of Beirut 1953–1956. Dr. Columbia 1960–1969, Woods Hole Oceanographic Institution 1969–1985, then NAS...

Journal: : 2021

Many boreholes have been drilled between Černá Hora town and Závist village to evaluate geohazards that may affect the construction of a new road. The core material from was studied for translucent heavy minerals microfossil content. Translucent mineral assemblages sands are often dominated by staurolite. Cyanite, tourmaline, rutile andalusite, typical Cenomanian sediments Moravia common. Relat...

2005
Andrew H. Knoll Michael Carr Benton Clark David J. Des Marais Jack D. Farmer Woodward W. Fischer John P. Grotzinger Scott M. McLennan Michael Malin Christian Schröder Steven Squyres Nicholas J. Tosca Thomas Wdowiak

Sedimentary rocks exposed in the Meridiani Planum region of Mars record aqueous and eolian deposition in ancient dune and interdune playa-like environments that were arid, acidic, and oxidizing. On Earth, microbial populations have repeatedly adapted to low pH and both episodic and chronic water limitation, suggesting that, to a first approximation, the Meridiani plain may have been habitable d...

2016
D.M. Bower A. Steele M.D. Fries O.R. Green J.F. Lindsay

The utility of nondestructive laser Raman for testing the biogenicity of microfossil-like structures in ancient rocks is promising, yet results from deposits like the ∼3.46 Ga Apex chert remain contentious. The essence of the debate is that associated microstructures, which are not purported to be microfossils, also contain reduced carbon that displays Raman D- and G-band peaks similar to those...

2015
NICOLE S. KHAN CHRISTOPHER H. VANE BENJAMIN P. HORTON CAROLINE HILLIER JAMES B. RIDING CHRISTOPHER P. KENDRICK

We examined the use of dC, TOC and C/N geochemistry of sedimentary organic matter to reconstruct former sea levels and paleoenvironments in the absence of suitable microfossil data. The modern distribution of dC, TOC and C/N of 33 vegetation and 74 surface sediment samples collected from four coastal wetlands in the Thames Estuary and Norfolk, UK are described. The dC, TOC and C/N geochemistry ...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه اصفهان - دانشکده علوم 1387

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